Genome engineering is an emerging field in which site specific rare cutting endonucleases are used to create DNA double strand breaks at desired genomic sites. Endonuclease-induced double strand breaks are resolved by endogenous DNA repair pathways, resulting in high efficiency gene editing if resolved via nonhomologous end joining, or targeted gene modification if resolved via homologous recombination. Precision Genome Engineering has developed proprietary methods for generation and isolation of rare cutting endonucleases based on surface display of LAGLIDADG homing endonuclease scaffolds. This phase I STTR will support the application of this approach to generate novel LAGLIDADG nucleases capable of cleaving the HIV POL gene. These nucleases will be applicable in novel approaches to therapy of latent HIV infection. Utilization of such an endonuclease to cripple latent HIV genomes and/or make cells resistant to HIV infection represents a new approach to treatment of established HIV infections. PERFORMANCE SITE(S) (organization, city, state) 1) Precision Genome Engineering Inc. 454 N. 34th Street Seattle, WA 98103-8602 2) Seattle Children's Research Institute/Scharenberg Lab Center for Immunity and Immunotherapies, 7th floor (Suite 700). 1900 9th Ave Seattle, WA 98104 3) Fred Hutchinson Cancer Research Center/Jerome Lab 1100 Fairview Ave Seattle, WA 98101 PUBLIC HEALTH RELEVANCE: This project will support development of three engineered site specific nuclease capable of cleaving the HIV POL gene. These proteins or refined derivatives will be applicable to therapy of latent HIV infection.